Species richness, endemism and species composition in the tropical Afroalpine flora
Species richness, endemism and species composition in the tropical Afroalpine flora
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DOI：
10.1007/s00035-014-0132-0
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发表时间：
2014-10-01
期刊：
影响因子：
2.7
通讯作者：
Linder, H. P.
中科院分区：
文献类型：
--
作者：
Gehrke, Berit;Linder, H. P.
海洋岛屿上的植物物种丰富度和特有性取决于岛屿的年龄、大小、海拔和距离最近的移民来源的距离。大陆的“岛屿”系统，例如非洲山区适应寒冷的热带高山植物群，研究得较少。在这里，我们分析了热带非洲高山植物群，这些植物群分布在横跨赤道的高度孤立的山脉上。通过结合协调方法和壁炉测试的分层聚类方法中的beta-sim指数，我们确定了四个地理群体：西非、东非北部、东非西部和东非东部。我们表明，这些分组更好地解释为地理隔离的结果，而不是环境过滤。我们进一步表明，热带非洲高山地区的物种丰富度——类似于海洋岛屿——可以用一个包括年龄、面积大小、海拔和隔离的模型来解释。物种丰富度与面积和隔离度的结合可以很好地解释特有程度。总的来说，我们建立了一个关于热带非洲高山植物区系的物种丰富度、特有性和组成的综合模型。
Plant species richness and endemism on oceanic islands is dependent on island age, size, elevation and distance to nearest source of migrants. Mainland 'island' systems, such as the cool-adapted tropical-alpine flora of the mountains in Africa, are less well studied. Here we analyse the tropical Afroalpine flora, found on highly isolated mountains straddling the equator. Using the beta-sim index in a hierarchical clustering approach combined with ordination methods and mantel tests, we locate four geographical groups: West Africa, northern East Africa, western East Africa and eastern East Africa. We show that these groupings are better explained as the consequence of geographical isolation rather than environmental filtering. We further show that the species richness of the tropical Afroalpine mountain regions-similar to oceanic islands-can be explained by a model including age, area size, elevation and isolation. Levels of endemism are best explained by species richness in combination with area and isolation. Overall we develop a comprehensive model of the species richness, endemism and composition of the tropical Afroalpine flora.